Steering gear with steering drop arm

Claim 1

In a steering gear with steering drop arm, steering tie rod and steering gear connecting tie rod for a vehicle which is drivable on the road and in terrain on wheels, with a steering mechanism which is actuated selectively hydraulically supported mechanically or purely hydraulically by means of hydraulic cylinders and electromagnetic valves, and a universal shaft which is connected with the steering wheel changing from the hydraulically supported system over to the purely hydraulically operating system by selectively connecting said universal shaft with one of two systems which serve the actuation of the steering mechanism, wherein in combination. one of said systems comprises a steering transmission and the other of said systems includes a steering valve, said steering transmission and said steering valve being selectively actuated by said steering gear by selective connection with said universal shaft, respectively, said hydraulic cylinders include hydraulic cylinders of a front axle and hydraulic cylinders of a rear axle of the vehicle, a hydraulic pump operatively connected to both of said systems, motor means for driving said pump, a plurality of control valves, a flow control- and pressure limit- valve, a first conduit being connected to the latter and to said pump, a second conduit connected between said flow control- and pressure limit- valve and a first of said control valves, a first line being connected to said first control valve and to said steering transmission, second lines are connected to said steering transmission to a second of said control valves, third lines connecting said second control valve with said hydraulic cylinders of a front axle of the vehicle, a fourth line being connected to said first control valve and to said steering valve, a first selective operative pressurized oil flow path comprising in order: a fifth line being connected to said steering valve and a third of said control valves, said third control valve, and a sixth line being connected to said hydraulic cylinders of the front axle; a second selective operative pressurized oil flow path comprising in order: a seventh line being connected to said steering valve and to a fourth of said control valves, said fourth control valve, an eighth line being connected to said third and fourth control valves, said third control valve, and a ninth line being connected to said third control valve and to said hydraulic cylinders of the front axle; tenth lines connecting said fourth control valve with said hydraulic cylinders of the rear axle, a third selective pressurized oil operative flow path comprising in order: said fifth line connecting to said third control valve, said sixth line connecting to said hydraulic cylinders of the front axle, said ninth line connecting to said third control valve, said third control valve, said eighth line, said fourth control valve, and one of said tenth lines connecting to said hydraulic cylinders of the rear axle; a fourth selective operative pressurized oil flow path comprising in order: said seventh line connecting to said fourth control valve, said fourth control valve, one of said tenth lines connecting to said hydraulic cylinders of the rear axle, the other of said tenth lines connecting to said fourth control valve, said fourth control valve, said eighth line, said third control valve, and said ninth line connecting to said hydraulic cylinders of the front axle; said control valves being selectively switched such that any one of said selective operative flow paths is operative with flow of pressurized oil therethrough.